I will have new stock from a new supplier arriving end of next month. I can bring them down to the RSOC day at Birdwood for you. Have Forest front and rear, along with front spoilers.
The ugly ones I had are now all sold.

I think what it is, is that the rear of the front arches on the fibreglass ones do not 'tuck' back into the chassis. As shown in the pictures above they don't return back flat they stay with some width. 

matt
 
 most if not all fiberegass arches a "forrest archs" because they are easy to replace after bummping into trees. The ones of the car you posted up are "tarmac archs" normal alloy not so easy to replace and ar hard fixed with rivets or blended into the panel work
 
stu

I ended up getting a set from marty mexico. A fibreglass set which are tarmacs. They look really great. Top bloke as well!

out of curiosity, the arches in geoffs picture sit below the body line whereas the the blue car in mattsmith's jpg are mounted really high up the side panels. Is that the difference between forest and tarmac arches ?

Forest arches are usually below the swage line. Tarmacs are a bit above, there are monte carlos which are massive. There is huge variation between each person. The ones I'm getting are halfway between the swage line and the window. The ones in the picture are a bit too high! The fronts are supposed to be the same (according to some sources) but fibreglass fronts seem to differ. The forests stay out at the bottom while the tarmacs go back in (much cleaner imho)